Johninnesite is a rare manganese magnesium silicate mineral known primarily from the zinc deposits of Franklin and Sterling Hill. Collectors typically look for its characteristic pink to brownish-pink fibrous or needle-like crystals often found growing in association with other rare fluorescent Franklin minerals.
Is this johninnesite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch johninnesite with a known reference. Johninnesite sits at Mohs 4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Johninnesite leaves a light brownish yellow streak.
- 3Read the lusterHold the specimen under a strong light. Johninnesite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: light yellowish brown.
- 5Look at form & habitCrystal system: triclinic. Typical habit: fibrous, acicular, prismatic crystals, radiating clusters.
Often confused with
Johninnesite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside johninnesite
Minerals reported to co-occur with johninnesite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₂Mn₇Mg₂Si₁₂As₂O₃₆(OH)₆
- Mohs hardness
- 4
- Density
- 3.55 g/cm³
- Colors
- Streak
- Light Brownish Yellow
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Fibrous, Acicular, Prismatic Crystals, Radiating Clusters
- Cleavage
- Good On {100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphosed Zinc Ore Bodies
Where rockhounds find johninnesite
Classic worldwide localities
- Kombat mine, located 37 km east of Otavi and 49 km south of Tsumeb in the north-central part of Namibia
Field-hunting tip
Look in metamorphosed zinc ore bodies country, the host setting where johninnesite typically forms. If you start seeing willemite, franklinite, zincite in float, you are in the right ground. Field specimens usually show a fibrous, acicular, prismatic crystals, radiating clusters habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify johninnesite?+
Where is johninnesite found?+
Is johninnesite safe to handle?+
What rocks look like johninnesite?+
What minerals are found with johninnesite?+
What kind of rock does johninnesite form in?+
What is johninnesite used for?+
Find johninnesite on the map
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